In communication services currently provided by communication providers the sequence that packets from plural users at geographically separate locations sent to the same destination enter the service provider network and the sequence that packets at the destination exit the network are not always equal due to transmission delays occurring due to the physical distance between the user and destination or between users.
So in the case of transactions (electronic commerce transactions such as the buying and selling of stocks and currencies over a network) whose results are determined by the sequence that the transaction is processed, even a slight time discrepancy caused due to the transmission delay generates a profit or loss between the parties involved so that fair and equal service to the users cannot be maintained.
In other words, if the processing request is transferred and executed by way of the network, the processing request sent to the network will be received and executed at the applicable server after a transmission delay that varies according to factors such as the physical distance to the server doing the processing. So in other words the sequence that the process request is received and executed depends not only on the transmit sequence but also on the transmission delay time that occurs in this communication process. One method to resolve this problem is to attach a timestamp to the processing request from the user and then rearrange the (request) sequence at the server processing the transactions.
In Japanese Unexamined Patent Application Publication NO. Hei11 (1999)-259386, the server for performing the transaction contains a function to time-synchronize with the terminal utilized by the user and attach a timestamp to the processing request the user sent from the terminal. This server processes the processing requests in the order that the requests were sent, arraying the request sequences based on the timestamp attached to the processing request rather than the sequence in which the processing request was received. This operation is described below in more detail.
The client machine periodically receives the absolute time from the time server, and corrects the time on the timer of the client machine by utilizing the received absolute time. Each client machine sends a service data request and time data (absolute time) from the timer for receiving various services to the server machine byway of the Internet. The control unit in the server machine sorts the service data requests stored in sequence in the memory device in the order of earliest absolute time, based on the time data (absolute data) attached to the service data request. The server machine also contains a timer to count the time from the time that the service data request from each client machine arrived at the control unit. The server machine sets the maximum transmission time between the server machine and each client machine as the maximum delay time, and utilizing the timer contained within the server machine, processes the service data request after storing the maximum delay time among the service data request in the storage device.